Method of indirectly connecting two parts

Abstract

Two parts, such as a quartz part and piezo-electric part, are indirectly connected to one another by applying relatively thin metallic layers having a thickness of about 0.5 nm to 55 nm under vacuum conditions onto the surfaces of such parts to be joined and then without ventilation of the vacuum-chamber contacting the free surfaces of such metallic layers with one another under the maintained vacuum conditions whereby a substantially permanent bond is formed between such layer.

We claim as our invention: 
     
       1. In a method of indirectly connecting two parts in a vacuum-tight manner whereby metal layers are applied under vacuum to surfaces of such parts to be connected and free surfaces of such metal layers are brought into contact with one another under vacuum, the improvement comprising: applying said metal layers onto surfaces of such parts to be joined so that such layers have a thickness in the range of about 0.5 to 55 nm; and   maintaining such applied layers at about room temperature and under vacuum conditions while substantially simultaneously applying a pressure of up to about 10 N/cm 2  onto such parts to force free surfaces of said metal layers into intimate contact with one another.   
     
     
       2. In a method as defined in claim 1 wherein said metal layers are composed of a metal selected from a group consisting of titanium and chromium. 
     
     
       3. In a method as defined in claim 1 wherein applying said metal layers comprises applying a lower adhesive metal layer and applying an upper connecting metal layer. 
     
     
       4. In a method as defined in claim 3 wherein said lower adhesive metal layer is applied in a layer thickness ranging between about 0.5 to 5 nm and said upper connecting metal layer is applied in a layer thickness ranging between about 5 to 50 nm. 
     
     
       5. In a method as defined in claim 3 wherein said lower adhesive metal layer is composed of a metal selected from a group consisting of titanium and chromium and said upper connective metal layer is composed of a metal selected from a group consisting of gold, silver, platinum, copper, aluminum and indium. 
     
     
       6. In a method as defined in claim 1 wherein the surfaces of the parts to be joined are, prior to application of said metal layers thereto, machined to a planeness of less than about 1 micron and a roughness depth of less than about 0.1 micron. 
     
     
       7. In a method of indirectly connecting two parts whereby metal layers are applied under vacuum to surfaces of such parts to be connected and free surfaces of such metal layers are brought into contact with one another under vacuum, the improvement comprising: providing, under vacuum conditions and prior to the application of said metal layers, an intermediate layer composed of lead-free glass and having a maximum thickness of about 100 nm onto a surface of at least one of said parts to be connected; and   applying said metal layers onto surfaces of said parts to be connected so that such metal layers have a thickness in range of about 0.5 to 55 nm.